Major hospital building projects are to get under way after ministers gave the green light to £1.5bn of PFI schemes.

Under PFI, private firms fund the projects with the NHS paying off the cost over a 20 to 30-year period.

Ministers said six schemes involving expanding A&E units, building a cancer centre and beefing up community services would be built by 2010.

But unions said PFI schemes were "expensive, inflexible and adding to financial burdens".

The decision comes as the BBC has learned that talks have begun in some parts of England over whether to strip emergency care from major hospitals and transferring them to nearby centres to create "super" hospitals.

PFI schemes are expensive, inflexible and are adding to the current financial burdens of many hospital trusts

Mike Jackson, of Unison

The government evaluated the PFI process earlier in the year amid criticism it was not providing value for money.

Earlier this year, the National Audit Office raised concerns over the financing of the Norfolk and Norwich University Hospital.

It said private investors made more than £80m out of a refinancing deal, but the hospital was only handed £34m.

In December, the Queen Elizabeth Hospital in Woolwich also cited PFI when admitting it had become technically insolvent.

Quality

But Health Minister Andy Burnham said he was confident the new projects would prove financially sound.

"Each scheme has been rigorously checked to make sure that it offers value for money and delivers services that are needed by local patients."

And he added: "This is great news for the hundreds of thousands of patients who will benefit from the modern, bright new buildings.

"The new facilities will not only be the best in terms of design and quality, but they will be affordable well into the future."

The new schemes are:

University Hospital North Staffordshire NHS Trust - £272m scheme to build a new community hospital and cancer centre

There are 58 NHS PFI schemes already open with another 30 in construction.

But Mike Jackson, senior national officer at Unison, said the schemes were a "waste of taxpayers' money".

"PFI schemes are expensive, inflexible and are adding to the current financial burdens of many hospital trusts."

Andrew Lloyd-Kendall, policy manager at the NHS Confederation, added: "We must make sure that the short-term cost-savings of these PFI schemes are balanced against the need to deliver long-term quality health services."